Which of the following is an authentication method that can be secured by using SSL?

A.
RADIUS

B.
LDAP

C.
TACACS+

D.
Kerberos

Explanation:
With secure LDAP (LDAPS), all LDAP communications are encrypted with SSL/TLS
Incorrect Answers:
A, C, D: None of these options have a version that is SSL encrypted.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, Sixth Edition, Sybex, Indianapolis, 2014, p 147.
http://en.wikipedia.org/wiki/Radius
http://en.wikipedia.org/wiki/TACACS
http://en.wikipedia.org/wiki/Kerberos_(protocol)